The present invention relates to an improved scroll saw, and more particularly to an automatic bearing adjustment mechanism which compensates for bearing play in the moving parts of the scroll saw.
Scroll saws or jigsaws include a saw blade connected between the free ends of the arms of a C-shaped member. The C-shaped member is reciprocated about a pivot shaft at the closed end of the C-shaped member in order to reciprocate or drive the saw blade. The saw includes a supporting frame that carries a reciprocating member for rapid reciprocation of the saw blade through an opening in a work table.
The present invention compensates for the wear of bearings mounted on the horizontal pivot shaft that is reciprocated for driving the saw blade. If the bearings become worn, the saw may either have excessive vibration or may not be able to hold the saw blade accurately relative to the work table. In U.S. Pat. No. 4,619,171, one type of bearing compensating mechanism is disclosed as applying a resilient inwardly directed force against bearings mounted on the horizontal pivot shaft, in order to hold the bearings in the desired position during use of the scroll saw. As compared to this prior art patent, the present invention seeks to compensate for bearing wear by applying an outwardly directed resilient force against one of the bearings, with an inwardly directed force also being applied through the horizontal pivot shaft to the other bearing, in order to compensate for bearing wear and thereby eliminate bearing play, as will be discussed in detail below.